My Community

Dear all,

I did Band structure calculation by using LSDA+U method.
But unfortunately I got incorrect result, different from those that are in literature.
Here is my INCAR for SCF:

SYSTEM = (Co O)6 (P1) ~ /home/medea/Desktop/CoO111/CoO.cif, phase System: CoO (VASP)

PREC = Normal

ENCUT = 400.000

IBRION = -1

NSW = 0

NELMIN = 2

EDIFF = 1.0e-05

EDIFFG = -0.02

VOSKOWN = 1

NBLOCK = 1

NELM = 60

ALGO = Normal (blocked Davidson)

ISPIN = 2

MAGMOM = 3 -3 3 -3 3 -3 6*0

LDAU = .TRUE.

LDAUTYPE = 1

LDAUL = 2 -1

LDAUU = 7.1 0

LDAUJ = 1 0

LMAXMIX = 4

LORBIT = 1

ICHARG = 2

INIWAV = 1

ISTART = 0

LWAVE = .TRUE.

LCHARG = .TRUE.

ADDGRID = .FALSE.

ISMEAR = 0

SIGMA = 0.1

LREAL = .FALSE.

RWIGS = 1.16 0.73

NPAR = 8

LPLANE = F



In NSCF I put

ISTART = 1

ICHARG = 11


and used CHG, CHGCAR and WAVECAR files from SCF.

Also, I used Medea for my calculation. Interesting is that when I chose only one option ?Band Structure calculation? I got incorrect result, but when I chose two options ?DOS calculation? and ?Band structure calculation? I got correct result.

Can someone explain me why I got this inconsistency? And what is the best way for doing calculation of band structure for insulators with strong correlation (CoO)?
I suppose that crucially important is ?ISMEAR? option. But for Band structure NSCF calculation we can't use ISMEAR = -5.

thanks a lot

Hi

Your system is an insulator, so ISMEAR doesn't have any influence (it's for fractional occupancies, i.e. metals). Try using ISMEAR=-5, it's better than a Gaussian smearing.

I don't know about Medea but what kind of inconsistency do you have? It is strange that activating an additional option leads to correct results....

Regards

Boris